Steel slag used in landfill cover liners: laboratory and field tests

Abstract

Stricter rules for landfilling within the EU have led to the closure of many landfills and a need for large amounts of cover liner materials. Therefore, the potential utilization of mixtures of electric arc furnace slag (EAFS) and ladle slag (LS), which are currently deposited in landfills, as a material for use as landfill liner was investigated. Laboratory analyses showed the mixtures to have similar compression strength to that of high-strength concrete and low hydraulic conductivity (< 10(-11) m s(-1) in some cases). However, both their hydraulic conductivity and compaction properties were strongly affected by the time between adding water to the mixtures and compacting them (tests showed that a delay of 24 h can lead to an increase in hydraulic conductivity, so it should be compacted as soon as possible after mixing the material with water). In addition, the performance of a cover liner constructed using EAFS and LS was studied in a 2-year field trial on a landfill for municipal solid waste, in which the average amount of leachate collected from ten lysimeters was only 27 L m(-2) year(-1), easily meeting Swedish criteria for the permeability of covers on non-hazardous waste landfills (≤ 50 L m(-2) year(-1)). Thus, the material seems to have promising potential for use in barrier constructions.

Reduction of acid rock drainage using steel slag in cover systems over sulfide rock waste piles

“…The minerals identified in ES1 by X-ray diffraction methods are: calcium oxide, CaO; wustita, FeO; quartz, SiO 2 ; and one other mineral of lesser concentrations.The values obtained by total acid digestion chemical analysis are described in Table 2. The results are similar to the results obtained by Pena (2004), Sousa (2007), Fernandes (2010) and Herrmann et al (2010).…”

“…Although this cover system allows an infiltrating water flux, the oxygen flux required to activate reactions (1) and (2) described above is blocked. Accordingly, Herrmann et al (2010) suggest that steel slag has a promising potential as a suitable cover layer material under the right conditions.…”

Assessment of bauxite refining residue (red mud) as a liner for waste disposal facilities

“…coal fly ash [42], steel slags [43], fly ash-sewage sludge mixtures [44] and bagasse ashsoil mixtures [45], among others, have attracted attention in recent years as substitutes for clay in hydraulic barriers. The reasons that may justify this replacement are: (i) natural clays or clayey soils are not always available and would have to be imported from elsewhere, thereby increasing construction costs; (ii) it provides a useful function for a material otherwise considered waste [37]; (iii) high susceptibility of clays to chemical attack by certain contaminants [46] and (iv) clays may not always provide good contaminant sorption properties (e.g.…”

Optimization of Mineralogy and Microstructure of Solidified Basic Oxygen Furnace Slag Through SiO2 Addition or Atmosphere Control During Hot-Stage Slag Treatment

“…In the past decades, metallurgical slag valorization has been intensively explored to apply the slag in various fields, such as landfill liner [4,5], hydraulic binder [6][7][8], and fertilizer [9]. Among these, hydraulic binder that can be used for constructional application appears to be more interesting as they create higher value.…”